US 3705479 A
An apparatus for providing a stream of substantially dry, evaporatively cooled air for use in dwellings and the like, characterized by the utilization of a high-speed blower for establishing a stream of air, a continuously rotating water-saturated pad interposed in the stream adapted to provide a radial discharge of moisture-ladened, evaporatively cooled air and a substantially dry perforated pad interposed in the stream of air between the blower and the periphery of the saturated pad for extracting moisture from the air, whereby a stream of relatively dry cooled air is provided.
Description (OCR text may contain errors)
Unitedv States Patent 11's] 3, 3,705,479
McPherson [451 Dec. 12, 1972 [541 APPARATUS FOR COOLING AIR 2,342,841 2/1944' Carraway, ..261/92 x 72 I nt w M I Carraway X 1 fith, 'l g E 2,809,817 10/1957 Munters; ..26l/83 x 3,306,591 2/1967 Valazza ..261/92 x 221 Filed: May 15,1969 3,365,862 1/1968 Flury ..55/230 21 A 1. N l 1 pp 824778 Primary Examiner-Dennis E. Talbert, Jr.
Attorney-Huebner & Worrel  US. Cl. ..55/223, 55/224, 55/226,
55/227, 55/232, 55/234, 55/259, 55/267,  ABSTRACT 55/410 55/418 55/467 7 An apparatus for providing a stream of substantially dry, evaporatively cooled air for use in dwellings and lil $533588 13575832 26 32"? tht hhtt thttttttthtth tht ttthhtthh t htth- 55,410 418 467 490 261/83 f speed blower for establlshing a stream of an, a cori- 62/531 f jtmuously rotating water-saturated pad interposed 1n the stream adapted to provide a radial discharge of I 'v t moisture-ladened, evaporatively cooled air and a sub-  'Rgferences Cited stantially dry perforated pad interposed in the stream UNITED STATES PATENTS of air bgtwegnfth'e blower, and the periphery hof the saturate pa or extracting moisture rom t e air,
whereby a stream of relatively d y cooled air is Pro- 9 9 6 leg on t d d 2,177,869 10/1939 Crawford ..261/92 X at 2,300,580 11/1942 Loprich ..26l/30 t 1 Claim, 3 Drawing Figures PKTE'NTEDnEcm 1972 3,705,479
WILSON W MC PHERSON INVENTOP A T TOR/1 E VS 1 APPARATUS FOR COOLING AIR BACKGROUND OF THE INVENTION stantially dry, evaporatively cooled air for purposes of reducing temperatures in dwellings, warehouses and the like.
The prior art includes numerous devices and systems for evaporatively cooling and delivering atmospheric air for purposes of cooling buildings. Normally, these devices force a stream of air through a water-saturated pad, whereby evaporation of water and a resulting cooling of the air is achieved as water within the pad is evaporated in the presence of the stream of air. One of the undesirable characteristics of such air is that air delivered through a wet pad usually becomes heavily ladened with moisture particles, aswell as water vapor. Since the conversion of water to water vapor cools by evaporation while the particlization of water does not, burdening the air with water particles is undesirable. Among the disadvantages incidentto the presence of moisture particles is the inability of cooling'devices of the evaporative type to function efficiently under such conditions. Evaporation is inhibited by the presence of excessive moisture and moisture-ladened air does not permit adequate evaporation from the body for personal comfort. Furthermore, delivery of excessively moist air for cooling purposes can be harmful to the environment and even result in indoor precipitation.
SUMMARY OF THE INVENTION This invention overcomes the aforementioned difficulties through the use of a novel arrangement of water absorbent, perforated pads employed in a manner such that a first pad is saturated with water and a stream of air is forced therethrough for achieving an evaporative cooling of the air, and a second pad is positioned in the stream and employed for extracting from the evaporatively cooled air, water particles suspended therein prior to the delivery of the thus cooled air.
Accordingly, an object of the instant invention is to provide an improved apparatus for evaporatively cooling ambient atmospheric air.
Another object is to provide an improved evaporative cooler for use in providing relatively dry, evaporatively cooled air.
Another object is to provide an efiicient evaporative cooler which employs a drum-mounted, continuously rotating pad partially submerged in a water bath for delivering relatively dry, evaporatively cooled atmospheric air for use in a relatively humid atmospheric environment.
Another object is to provide in an evaporative cooler variable speed drive means adapted to dictate the rates of rotation imposed on a drum-mounted .cooler pad, whereby the water content of air delivered through the pad effectively may be controlled.
Other objects and advantages of the present invention will subsequently become more clearly apparent upon reference to the following description and accompanying drawing.
2 BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a sectioned side view of an evaporative cooler embodying the principles of the present invention.
FIG. 2 is a sectioned end view taken generally along line 22 of FIG. 1.
FIG. 3 is a sectioned end view taken generally along line 3-3 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT Turning first to FIG. 1, therein is illustrated an evaporative cooler embodying the principles of the present invention mounted in a substantially closed housing 10. The housing includes suitable mounting brackets 11, a system intake duct 12, including a pair of coaxially arranged openings 13, FIG. 2, and a single system discharge duct 14, through which air is drawn into the cooler and discharged as a stream of substantially dry, evaporatively cooled air. By substantially dry is meant that it contains a minimum of water particles although, of course, it does contain water vapor.
Within the housing 10, adjacent to the intake duct 12, there is provided a water bath, generally designated 16. The water bath includes a water-tight pan 18 which receives and retains therein a replenishable supply of water. Within the pan there is displaceably disposed an arcuate segment of a cylindrical, pervious, evaporative cooler pad 20. The pad is open-ended, at both ends, and is arranged in coaxial alignment with the openings 13 of the intake duct 12 so that air drawn into the duct passes through the openings at ends of the pad and is radially discharged through the pad. The pad is formed of any convenient water absorbent material, such as excelsior, for example, and is supportedfor rotation by means including a cylindrical drum 22 which receives and supports the pad in a circumscribing relationship about its peripheral surface. The drum is rotated about its longitudinal axis and serves to displace the pad through the pan 18 for causing the material thereof to become water saturated as it passes through the water bath and to become evaporatively dried as air is radially discharged therethrough and for thus achieving desired evaporative cooling.
The drum 22 includes a pair of spaced end supports 24, each of which is of a generally disk-shaped configuration and includes a plurality of spoke-like members 26 extending radially from hubs 28. The supports 24 are disposed in parallel planes with the hubs being fixedly secured to an axle shaft 30 extended through the drum 22 along its axis of rotation. It is intended that the axle shaft 30 serve to support the drum and impart selected rates of rotation thereto. Therefore, the hubs 28 are secured to the shaft by any convenient means, such as setscrews 32, for preventing rotation of the axle shaft relative to the hubs so that a driving connection is established therebetween.
The spaced supports 24 are interconnected by any convenient means. However, as presently employed, the distal ends of the spokes 26 are secured to a plurality of connecting stringers 34 which extend to couple the members 24 into a unitary drum-like structure having an axle extended therethrough. It should readily be apparent that the members 24 can be joined through various types of connecting members, such as perforated screens or cylinders having perforated walls, for example. Furthermore, if desired, the pad itself may be of a relatively rigid construction so that the pad is supported without requiring the use of additional support means. In any event, it is to be understood that the cylindrical pad 20 is supported for rotation by the drum 22 which is, in turn, supported for rotation by the axle 30 so that successive segments of the pad 20 are advanced through the water bath 16 for achieving a saturation thereof, and through the established air stream for achieving an evaporation of the water from the pad.
The opposite ends of the axle 30 are received within and are supported by convenient structure including a pair of spaced bearing supports 36. Each of the sup ports 36 includes a bearing housing 38 within which there is arranged convenient bearings, not shown. Each bearing housing is arranged in a coaxial relationship with the drum 22 with the supports therefor being rigidly fixed to the housing thereby to provide a rigid support for the opposite ends of the axle 30 so that the drum 22 is supported for rotation.
It isto be understood that the drum 22 is continuously driven in rotation at selected rates so that successive segments of the pad 20 cyclically are wetted and subjected to the stream of air thus to achieve the desired heat absorption by evaporation of the water, whereby the temperature of the air of the stream is reduced. In order to achieve the required driving of the drum, a variable-speed motor 40, of any convenient design, is fixedly secured to the housing 10 through convenient mountings, such as stud bolts 42, and coupled to the drum through a drive train including a V- belt 44. As illustrated, the V-belt 44 is trained about and extends between a pair of sheaves 46 and 48 coupled to the output shaft 49 of the motor 40, and to the axle 30 respectively.
The motor 40, through the belt 44 and its associated sheaves 46 and 48, drives the drum 22 at variable rates of rotation as dictated by selected cooling rates for the prevailing climatic and atmospheric conditions. In practice, a rate of approximately 4 revolutions per minute has been found practical under most conditions, however, the rate is varied as is required to achieve a desired cooling effect.
While the motor 40 is a variable-speed motor, it should readily be apparent that by varying the diameter of the sheaves 46 and 48, a speed reduction drive may readily be provided so that a constant speed motor can be employed, where desired. The manner, in which the rate of rotation imparted to the drum 22 is varied, is a matter of convenience, therefore, any suitable drive coupling may be employed in lieu of a belt drive.
Water is introduced into the pan 18 of the water bath 16 through any convenient supply system. As illustrated, a valve-controlled inlet 50 is coupled with a water input conduit 52, the output of which is controlled through a convenient valve associated float 54. The float is formed of a buoyant material and rides" at the upper surface of the water retained within the pan and includes an extended arm coupled with a convenient valve, not designated, for the inlet so that the inlet 50 may be opened and closed in response to changes established in the water level of the pan 16 as the water is extracted by the pad 20.
Therefore, it should be appreciated that as atmospheric air is drawn through the intake duct 12, it is introduced axially into the drum 22 and radially discharged from the periphery of the pad 20 in a watersaturated state. As the air egresses from the drum and periphery of the pad 20, the temperature thereof is reduced through the resulting evaporation processes. However, the air in passing through the pad also tends to acquire particles of moisture. Consequently, the air as it is introduced into the housing 10 is damp and contains a substantial quantity of minute particles of water delivered thereto as the air is passed through and from the water-saturated pad 20.
However, as a flow of air is established between the periphery of the pad 20 and the discharge duct 14, the moisture particles are removed by a substantially dry, water-absorbent cooler pad 54 seated in a convenient bracket 55 and positioned in the path of the flow of air being delivered to the discharge duct. The removed particles ultimately are evaporated for thereby extracting additional heat from the stream. The pad is formed of any convenient material which is capable of absorbing moisture as the air is delivered therethrough. Such pads are commercially available and therefore a detailed description is omitted in the interest of brevity. However, if desired, the pad 54 may be formed of a material similar to that employed in forming pad 20.
In order to impel the flow of air from the periphery of the pad 20, through the pad 54 and through the discharge duct 14, a relatively high-speed blower 56 is provided upstream of the discharge duct 14. This blower is so arranged as to have its discharge arranged in coaxial alignment with the duct 14. While the blower 56 may be of any convenient design, as presently employed, the blower is a radial-discharge, drum-type blower. As the specific blower employed may be varied and since such devices are commercially available, a detailed description of the blower is omitted. Generally, however, the blower 56 includes a cylindrical drum 58 of an open-end configuration, having a multiplicity of radially extended, air-dispelling blades 60. The drum is supported for rotation about an axis of rotation by a laterally extended axle 62, the ends of which are seated for support within convenient bearing housings 64.
The drum 58 is enclosed within a convenient blower housing having an intake 72 provided therefor. The intake 72 includes coaxially arranged openings 73 through which air is introduced. As the drum 58 is driven in rotation, air is introduced at opposite sides of the housing 70 through the intake duct 72, axially of the drum 58, and is discharged therefrom in radial directions for thereby driving the air through the discharge duct 14. In practice, the drum 58 is driven at a relatively high rate of rotation whereby the flow of air is accelerated to establish a relatively high velocity stream of air as it is passed from pad 20 through the pad 54.
It is to be understood that the drum 58 is driven at selected rates of rotation compatible with the extraction of particles of moisture from the air as well as to establish the pressures required in delivering the stream of air to its point of utilization. As a practical matter, a rate of rotation of approximately 400 revolutions per minute has been found to be quite adequate for the purposes of delivering air through the cooler.
In practice, a variable-speed motor 74, fixed to the housing by studs 75, is coupled with the drum 58 through a pair of sheaves 76 and 78 and an interconnecting V-belt 80 in a manner quite similar to that in which the motor 40 is coupled with the sheave 48 for driving the drum 22. It is to be understood that the drum 58 is driven by the motor 74 at a rate sufficient to establish a desired How of air between the pad 20 and the pad 54 and that this flow continuously is accelerated as it passes from the pad 20 through the pad 54 into the discharge duct 14 of the housing 10.
While various access doors may be provided for the housing 10 and employed in seating the pad 54 within the bracket 55, a conveniently hinged access door 84 is presently employed for accommodating an insertion of the pad 54 into the brackets 55. With reference particularly to FIG. 1, it will be noted that the access door 84 also includes an additional door or flap 86 pivotally connected at its distal edge. With this arrangement, there is established an auxiliary opening 88 communicating with the flow of air being delivered to the blower 56, so that ambient atmospheric air may be introduced through the pad 54 and into the stream of air being delivered to the intake duct 72 of the blower 56. This arrangement accommodates greater versatility in controlling the temperature and the level of liquid moisture present as the air is delivered from the duct 14. Since the flap 86 is pivotally connected to the door 84, itis to be understood that it selectively may be closed for thus closing the opening 88 against passage of atmospheric air.
OPERATION The operation of the described embodiment of the subject invention is believed to be clearly apparent and is briefly summarized at this point. While the cooler embodying the principles of the present invention may be mounted'at any convenient location, as presently employed, it is supported adjacent to a building to be cooled. It is to be understood that the duct 14 is connected with a convenient conduit, not shown, which serves to deliver the cooled air from the discharge duct 14 to selected points of utilization.
With the cooler mounted, by brackets 11 and connected with a convenient voltage source suitable for energizing the motors 40 and 74 and connected with a convenient supply of water, the cooler is prepared for operation.
As the motor 40 through the belts 44 and sheaves 46 and 48 serves to drive the drum 22 in rotation, the pad 20 continuously is passed through the water bath 16 and saturated by the water contained within the pan 18. Concurrently, with the driving of the drum 22, the drum 58 of the blower 56 is driven at a relatively high rate of rotation by the motor 74 acting through the associated belt 82 trained about the sheaves 76 and 78. As the drum 58 is driven, the blades 60 expel air radially therefrom causing a stream of air to be accelerated axially into the drum through the openings 73 of the blowers intake duct 72. Consequently, a vacuum condition is established adjacent to the periphery of the pad 20 so that atmospheric air is forced through the system intake duct 12 and expelled radially through the pad 20. As the air is taken axially into the duct 12 and is driven through the pad 20, evaporation of the water within the pad occurs. As the water is converted to a vapor, heat is extracted from the air causing the temperature thereof to be reduced.
Since vaporization is incomplete, the air inherently includes suspended minute particles of moisture in liquid form as the flow of air egresses from the peripheral surface of the pad 20 towards the blower 56.
As the air containing the particles of moisture is conducted toward the intake duct 72, of the blower 56, it is passed through the relatively dry moisture-absorbent pad 54 which serves to extract the particles of moisture therefrom so as to accommodate the establishment of a relatively dry, evaporatively cooled stream of air as the stream of air is accelerated to the intake duct of the blower. The pad 54 tends to remain dry due to an induced evaporation of the trapped moisture. This evaporation serves to further cool the air.
When the flap 86 is lifted, ambient atmospheric air is introduced through the opening 88 and a mixture of cooled dry air and ambient atmospheric air is achieved for the sake of controlling temperature and moisture content for the air as it is discharged from the system discharge duct 14.
Although the invention has been herein shown and described in what is conceived to be the most practical and preferred method and apparatus, it is recognized that departures may be made therefrom within the scope of the invention.
1. An evaporative cooler comprising:
A. a substantially closed housing having means defining an atmospheric air intake duct and a cool air discharge duct disposed in a spaced, communicating relationship for continuously conducting a standing stream of air through said housing;
B. means adjacent to the air intake duct defining a water bath within the housing;
C. a cylindrical pad formed of a pervious, water-absorbent material including an open end disposed adjacent to the air intake duct for axially receiving said stream;
D. a drum concentrically supporting said cylindrical pad about the periphery thereof including a concentrically related axle extending from the opposite ends thereof;
E. a pair of laterally spaced, vertically oriented supports secured to the housing adjacent to the water bath and coupled with said axle for supporting said drum above said water bath in a manner such that a segment of the cylindrical pad continuously is submerged therein;
F. a first variable-speed drive unit operatively associated with said drum for driving the drum at a selectively variable rate, whereby said stream is directed radially through said pad and successive segments of said pad are wetted and subjected to said stream of air at a selectively variable rate for thus evaporatively cooling the air at a selectively variable rate;
G. a high-speed blower operatively supported within said stream, adjacent to the cool air discharge duct, for accelerating said stream of air as it is directed through said cylindrical pad and for discharging the stream of airfrom the discharge duct;
H. a second variable-speed drive unit operatively associated with said high-speed blower for driving the blower at a selectively variable rate, whereby said stream is accelerated and subsequently discharged through said discharge duct at a selectively variable rate;
. a substantially dry, planar pad formed of a pervidischarge from the cool air discharge duct, so that moisture particles introduced into the stream by said cylindrical pad as the stream is directed therethrough are absorbed by said substantially dry pad; and
. an auxiliary atmospheric air intake unit means associated with said discharge duct and ambient atmosphere for introducing atmospheric air only through said planar pad into said cool air discharge duct and mixing with the air in said cool air discharge duct.